Mad Cow Disease

Topic summary contributed by volunteer(s): Laura H.

Mad Cow Disease, also called bovine spongiform encephalopathy is an irreversible nerve tissue disorder that occurs when certain proteins in the brain go awry, folding abnormally. These twisted proteins called prions replicate, spreading throughout the animal’s brain, destroying brain function and ultimately leading to death.

Can Humans Get Mad Cow Disease?

Humans can develop a similarly devastating disorder called Creutzfeldt-Jakob disease. Neither of these diseases is contagious unless the brain or significant parts of the nervous system containing prions are ingested by another. For humans, this has only been a problem in parts of the world where cannibalism is practiced. For cows, contagion has thought to have occurred with the practice of feeding livestock with its own meat by-products. This forced bovine cannibalism has produced meat that when consumed, infected humans with a variant of the brain-wasting protein. Several ‘human cases’ of Mad Cow disease (officially called variant Creutzfeldt-Jakob disease or vCJD) were isolated in the United Kingdom leading to global concern. In the United States, the practice of feeding cows to cows has been banned and legislation to restrict bovine brain and spinal cord from food distribution has been enacted.

Are Prions to be Found in Today’s Beef?

Food safety advocates call for extreme caution in monitoring the disease. A point of concern is that prions are not destroyed by normal cooking temperatures. The insidious proteins have been found to survive temperatures exceeding 800 degrees Fahrenheit. Another point of contention is the fact that vCJD produces many of the same symptoms as dementia and in theory, is frequently misdiagnosed as early-onset Alzheimer’s disease.